A spatially explicit, empirical estimate of tree-based biological nitrogen fixation in forests of the United States
Anika Staccone, Wenying Liao, Steven S. Perakis, Jana Compton, Christopher L. Clark, Duncan Menge
2020, Global Biogeochemical Cycles (34)
Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom‐up approaches to quantify tree‐based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska....
Sensitivity of warm water fishes and rainbow trout to selected contaminants
John M. Besser, Rebecca A. Dorman, Chris D. Ivey, Danielle M. Cleveland, Jeffery A. Steevens
2020, Bulletin of Environmental Contamination and Toxicology (104) 321-326
Guidelines for developing water quality standards allow U.S. states to exclude toxicity data for the family Salmonidae (trout and salmon) when deriving guidelines for warm-water habitats. This practice reflects the belief that standards based on salmonid data may be overprotective of toxic effects on other fish taxa. In acute tests...
Plastic faulting in ice
Narayama Golding, William B Durham, David J Prior, Laura A. Stern
2020, Journal of Geophysical Research- Solid Earth (125)
Plastic faulting is a brittle‐like failure phenomenon exhibited by water ice and several other rock types under confinement. It is suspected to be the mechanism of deep earthquakes and extreme cases of shear localization in shallow rocks. Unlike ordinary Coulombic failure, plastic faulting is characterized by...
Flea sharing among sympatric rodent hosts: implications for potential plague effects on a threatened sciurid
Amanda R. Goldberg, Courtney J. Conway, Dean E. Biggins
2020, Ecosphere (11)
For vector-borne diseases, the abundance and competency of different vector species and their host preferences will impact the transfer of pathogens among hosts. Sylvatic plague is a lethal disease caused by the primarily flea-borne bacterium Yersinia pestis. Sylvatic plague was introduced into the western United States in the...
Co-occurrence and occupancy dynamics of mourning doves and Eurasian collared-doves
Adam W. Green, Helen Sofaer, David L Otis, Nicholas J. Van Lanen
2020, Journal of Wildlife Management (84) 775-785
Understanding how land cover and potential competition with invasive species shape patterns of occupancy, extirpation, and colonization of native species across a landscape can help target management for declining native populations. Mourning dove (Zenaida macroura) populations have declined throughout the United States from 1965–2015. The expansion of the Eurasian collared‐dove...
Cryptic and extensive hybridization between ancient lineages of American crows
David Slager, Kevin Epperly, Renee Ha, Sievert Rohwer, Christopher W. Woodall, Caroline R. Van Hemert, John Klicka
2020, Molecular Ecology (29) 956-969
Most species and therefore most hybrid zones have historically been defined using phenotypic characters. However, both speciation and hybridization can occur with negligible morphological differentiation. Recently developed genomic tools provide the means to better understand cryptic speciation and hybridization. The Northwestern Crow (Corvus caurinus) and American Crow (Corvus brachyrhynchos) are...
Global physical controls on estuarine habitat distribution during sea levelchange: Consequences for genetic diversification through time
Greer A. Dolby, Arturo M. Bedolla, S. Bennett, David K. Jacobs
2020, Global and Planetary Change (187)
Determining the extrinsic (physical) factors controlling speciation and diversification of species through time is of key interest in paleontology and evolutionary biology. The role of sea-level change in shaping species richness patterns of marginal marine species has received much attention, but with variable conclusions. Recent work combining genetic data and Geographical Information Systems...
Hydrologic connectivity determines dissolved organic matter biogeochemistry in northern high-latitude lakes
Sarah Ellen Johnston, Robert G. Striegl, Matthew J. Bogard, Mark M. Dornblaser, David E. Butman, Anne M. Kellerman, Kimberly P. Wickland, David C. Podgorski, Robert G. M. Spencer
2020, Limnology and Oceanography (65) 1764-1780
Northern high‐latitude lakes are undergoing climate‐induced changes including shifts in their hydrologic connectivity with terrestrial ecosystems. How this will impact dissolved organic matter (DOM) biogeochemistry remains uncertain. We examined the drivers of DOM composition for lakes in the Yukon Flats Basin in Alaska, an arid region of low relief that...
"Modified Unified Method" of carp capture
Duane Chapman
2020, Fact Sheet 2020-3005
Populations of Hypophthalmichthys molitrix (silver carp) and Hypophthalmichthys nobilis (bighead carp), (together referred to herein as “bigheaded carp”) have increased exponentially in the greater Mississippi River Basin. Detrimental effects on native fish and economically important fisheries have occurred where these invasive, filter-feeding fish are abundant. The Unified Method, a harvest...
Mineral commodity summaries 2020
U.S. Geological Survey
2020, Report
Each chapter of the 2020 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The...
Groundwater withdrawals and regional flow paths at and near Willow Grove and Warminster, Pennsylvania—Data compilation and preliminary simulations for conditions in 1999, 2010, 2013, 2016, and 2017
Daniel J. Goode, Lisa A. Senior
2020, Open-File Report 2019-1137
In 2014, groundwater samples from residential and public supply wells in the vicinity of two former U.S. Navy bases at Willow Grove and Warminster, and an active Air National Guard Station at Horsham, Bucks and Montgomery Counties, Pennsylvania, were found to have concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate...
The influence of pre-fire growth patterns on post-fire tree mortality for common conifers in western U.S. parks
Phillip J. van Mantgem, Donald A. Falk, Emma C. Williams, Adrian J. Das, Nathan L. Stephenson
2020, International Journal of Wildland Fire (29) 513-518
Fire severity in forests is often defined in terms of post-fire tree mortality, yet the influences on tree mortality following fire are not fully understood. For trees that are not killed immediately by severe fire injury, pre-fire growth may partially predict post-fire mortality probabilities for conifers of the western U.S....
High-resolution imaging of hydrothermal heat flux using optical and thermal Structure-from-Motion photogrammetry
Aaron Lewis, Robert Sare, Jennifer L. Lewicki, George Hilley
2020, Journal of Volcanology and Geothermal Research (393)
Quantifying hydrothermal heat flux at meter-scale resolution over N0.25 km2 is required to bridge in-situ heat flux and satellite-based measurements. We advance a methodology that blends ground-based daytime optical and nighttime thermal infrared (TIR) imagery using Structure-from-Motion photogrammetry to map radiant hydrothermal heat flux over these scales at sites with...
Northward migration of the Oregon forearc on the Gales Creek fault
Ray Wells, Richard J. Blakely, Sean Bemis
2020, Geosphere (16) 660-684
The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset...
Phylogeographic analysis of Mudpuppies (Necturus maculosus)
Katherine Greenwald, Amber Stedman, David Mifsud, Maegan Stapleton, Krista Larson, Donna L. Parrish, Isaac Chellman, C. William Kilpatrick
2020, Journal of Herpetology (54) 78-86
The geology of the Pleistocene, and particularly the Last Glacial Maximum approximately 26.5 ka, is a critical driver of species’ present-day distributions and levels of genetic diversity in northern regions. Using mitochondrial DNA sequence data, we tested several predictions relating to the postglacial recolonization of the northern United States and...
A weight-of-evidence approach for defining thermal sensitivity in a federally endangered species
Heather Galbraith, Carrie J. Blakeslee, Daniel E. Spooner, William A. Lellis
2020, Aquatic Conservation: Marine and Freshwater Ecosystems (30) 540-553
1. Managing for threatened and endangered species under changing environmental conditions is a challenge faced by resource managers worldwide. Lack of basic knowledge of the biology and habitat requirements of these species can contribute to this difficulty, but is confounded by the limitations of working with rare (i.e. few individuals)...
Did ice-charging generate volcanic lightning during the 2016–2017 eruption of Bogoslof volcano, Alaska?
Alexa R. Van Eaton, David J. Schneider, Cassandra Marie Smith, Matthew M. Haney, John J. Lyons, Ryan Said, David Fee, Robert H. Holzworth, Larry G. Mastin
2020, Bulletin of Volcanology (82)
The 2016–2017 shallow submarine eruption of Bogoslof volcano in Alaska injected plumes of ash and seawater to maximum heights of ~ 12 km. More than 4550 volcanic lightning strokes were detected by the World Wide Lightning Location Network (WWLLN) and Vaisala’s Global Lightning Dataset (GLD360) over 9 months. Lightning...
Discrimination of biological scatterers in polarimetric weather radar data: Opportunities and challenges
Sidney Gauthreaux, Robert H. Diehl
2020, Remote Sensing (12)
For radar aeroecology studies, the identification of the type of scatterer is critically important. Here, we used a random forest (RF) algorithm to develop a variety of scatterer classification models based on the backscatter values in radar resolution volumes of six radar variables (reflectivity, radial velocity, spectrum width, differential...
Modeling pathogen dispersal in marine fish and shellfish
Danielle L Cantrell, Maya L. Groner, Tal Ben-Horin, Jon Grant, Crawford W. Revie
2020, Trends in Parasitology (36) 239-249
Bio-physical models are a useful tool for understanding dispersal and transmission of marine pathogens. While utilized for larval dispersal models, they are only recently being used in epidemiological studies and are currently underutilized by the marine epidemiology field. Bio-physical models are useful for spatial planning and coastal management. For example, they...
Mule deer habitat selection following vegetation thinning treatments in New Mexico
Grant E. Sorensen, David W. Kramer, James W. Cain III, Chase A. Taylor, Philip S. Gipson, Mark C. Wallace, Robert D. Cox, Warren B. Ballard
2020, Wildlife Society Bulletin (44) 122-129
Mule deer (Odocoileus hemionus) survival and population growth in north-central New Mexico, USA, was previously reported to be limited by nutritional constraints due to poor forage conditions in degraded habitats. Management recommendations suggested thinning of pinyon–juniper to improve habitat quality for mule deer. To evaluate the...
Effect of copper salts on hydrothermal oxidative decarboxylation: A study of phenylacetic acid
Xuan Fu, Megan Jamison, Aaron M. Jubb, Yiju Liao, Alexandria Aspin, Kyle Hayes, Christopher R. Glein, Ziming Yang
2020, Chemical Communications (London) (56) 2791-2794
Decarboxylation of carboxylic acids is favored under hydrothermal conditions, and can be influenced by dissolved metals. Here, we use phenylacetic acid as a model compound to study its hydrothermal decarboxylation in the presence of copper(II) salts but no O2. Our results showed a strong oxidizing role of copper in facilitating...
Coexisting seismic behavior of transform faults revealed by high-resolution bathymetry
George E. Hilley, Robert M. Sare, Felipe Aron, Curtis W Baden, Dave Caress, Christopher M. Castillo, Stephen C. Dobbs, Jared T Gooley, Samuel Johnstone, Frances Liu, Tim McHargue, Josie M Nevitt, Charles K. Paull, Lauren E. Shumaker, Miles M Traer, Holly H Young
2020, Geology (48) 379-384
Transform faults are known to have anomalously low rates of seismicity, but no direct observations reveal why this is the case. We use new, autonomous underwater vehicle high-resolution seafloor mapping to image the morphology of and offsets along transform fault segments in the Gulf of California. Fault splays...
What's in the hump of the humpback chub?
David Ward, Michael B. Ward
2020, Western North American Naturalist (80) 98-104
The function of the nuchal hump on adult humpback chub (Gila cypha) has been the subject of longtime conjecture. Hypotheses about the purpose of the hump range from it being a feature that confers hydrodynamic advantages in swift water to speculation about how the hump may have reduced predation vulnerability...
Category count models for adaptive management of metapopulations: Case study of an imperiled salamander
Katherine M. O’Donnell, Paul L. Fackler, Fred A. Johnson, Mathieu Bonneau, Julien Martin, Susan C. Walls
2020, Conservation Science and Practice (2)
Managing spatially structured populations of imperiled species presents many challenges. Spatial structure can make it difficult to predict population responses to potential recovery activities, and learning through experimentation may not be advised if it could harm threatened populations. Adaptive management provides an appealing framework when experimentation is considered too risky...
Feeding ecology drives lead exposure of facultative and obligate avian scavengers in the eastern United States
Vincent Slabe, James T. Anderson, Jeff L Cooper, Tricia A. Miller, Bracken Brown, Anna Wrona, Patricia Ortiz, John Buchweitz, David McRuer, Ernesto Dominguez-Villegas, Shannon Behmke, Todd E. Katzner
2020, Environmental Toxicology and Chemistry (39) 882-892
Lead poisoning of scavenging birds is a global issue. However, the drivers of lead exposure of avian scavengers have been understood from the perspective of individual species, not cross‐taxa assemblages. We analyzed blood (n = 285) and liver (n = 226) lead concentrations of 5 facultative (American crows [Corvus brachyrhynchos], bald eagles [Haliaeetus leucocephalus],...
